Few men alive have broken down more tape of Penn than Nurse, the Muay Thai expert who was part of Georges St. Pierre's team that successfully came up with a game plan to beat Penn in their heavily hyped welterweight title fight at UFC 94 in 2009.

As he was helping to prepare St. Pierre for Penn, Nurse found what he believes to be flaws in Penn's game, but he got bleary-eyed in the process.

"Everyone has holes," Nurse said. "Everyone. No question about it. But with B.J., there aren't many and it takes a long time to find them."

On Saturday, Nurse will be in Frankie Edgar's corner when Edgar challenges Penn for the lightweight title in the co-main event of UFC 112 at Ferrari World. And though he professes great respect for Penn, Nurse has no doubt that Edgar is capable of shocking the world and pulling off the upset.

"B.J. is awesome; he really, really is, and no one is going to say he's not," Nurse said. "But there's always somebody up-and-coming, and I think Frankie's that guy. There are times when things turn around and I think that time is now.

"For some reason, people underestimate Frankie. I saw him fight Sean Sherk and that honestly was the first time I really started to pay attention to him. I'd been watching him before that and I thought, 'This kid can be good some day.' But when I saw him fight Sherk, I said, 'Man, where did this guy come from? He can fight.' He's come a long, long way in the time I've been watching him, and I honestly believe he's ready to win this fight now."

There aren't a lot of folks who are giving Edgar much of a chance, especially since Penn's loss to St. Pierre and his subsequent dedication to his conditioning. Penn has become a different fighter and has performed at an exceptionally high level. He submitted Kenny Florian at UFC 101 and massacred Diego Sanchez at UFC 107 in performances that were jaw-dropping, to say the least.

UFC president Dana White has had a rocky relationship with Penn through the years, and the two were at a low ebb as Penn was preparing to fight St. Pierre. White didn't feel Penn was training properly, and Penn didn't appreciate hearing White say it publicly. White, though, is convinced that after Penn lost that fight, Penn realized he was right and needed to change his approach.

"Let's be honest: B.J. was coasting along on his talent," White said. "He's been around a long time now and he's getting a bit older, and I think he saw the window of opportunity starting to close a little bit.

"When he really thought about things after the GSP fight, I think he realized that it was time to turn it on and take things seriously. He did that and the results speak for themselves."

Edgar, though, is as calm and poised as a young fighter facing his first championship shot can be. He knows about all the long shots who have come through, how the 1969 "Amazin' Mets" won the World Series or the Joe Namath-led Jets upset the Colts in Super Bowl III. Someone had to break UCLA's 88-game winning streak in college basketball or Oklahoma's 57-game winning streak in college football.

No matter how great the opposition, it happens.

And Edgar, who has morphed from an elite wrestler into an elite mixed martial artist who is dangerous in any position, is convinced he'll find a way.

"In the past, I would have thought my conditioning would have been my big advantage," Edgar said. "But in B.J.'s past two fights, he's fought long fights and he's been great. It's going to be pressure under fire for me. I have to figure it out on the fly when I'm out there.

"I'm being understated in the approach to this fight a little bit, but I've been through it before. Sean Sherk – I wasn't supposed to win. Even my first fight in the UFC, Tyson Griffin, everyone was overlooking me. So this is a comfortable position. I've been here before and I know how to deal with it."

Penn has dealt with title pressure for years and clearly won't be overwhelmed. He's also not making the mistake he often fell into in the past. Gone are the days when he'll talk of holding championships in multiple weight divisions. Despite plenty of prodding, he's not willing to even consider a move to 170 pounds.

"I'm getting a little older now," said Penn, who is an ancient 32. "I've been around and I've learned a lot. I have to keep my focus on what is directly in front of me. Frankie Edgar is good in all areas, and I can't afford to look beyond this fight. It took me some time, maybe, but now I know, the only fight that matters is the one you're fighting right now."

That's especially true for Edgar, who can't be sure if he'll ever get another title opportunity if he doesn't take advantage of the one on Saturday. Win or lose, Penn will be in the mix for future championship fights, but Edgar knows he has a lot more riding on Saturday's outcome.

"This is the chance of a lifetime and it's up to me to do something about it," Edgar said. "I feel I'm ready to do whatever I have to do to get it."